A plane flies the first half of a 5600 km flight into the wind in 3.5 h. The return trip, with the same wind, takes 2.5 h. Find the speed of the wind and the speed of the plane in still air

One cell phone plan charges $20 per month plus $0.15 per minute used. a second cell phone plan charges $35 per month plus $0.10 per minute used. write and solve an equation to find the number of minutes you must talk to have the same cost for both calling plans.